1. Field of the Invention
The present invention relates generally to a toner cartridge and more specifically, to a toner cartridge that has a locking mechanism to effectively prevent leakage of toner.
2. Description of the Related Art
U.S. Pat. No. 6,542,709 discloses a toner cartridge including a casing for accommodation of toner, a guiding groove, which is formed on a bottom side of the casing and provided with a tube extending along an axial direction thereof, and a cover, which seals a distal end of the tube and has an outlet on a bottom side thereof for output of the toner. As shown in FIG. 3 and FIG. 5 of the aforesaid patent, the toner cartridge further has a sliding member provided with a barrel portion mounted on the cover and the tube, and a positioning block coupled with a positioning mechanism of a photocopier. Thus, the sliding member can be driven to move by the positioning mechanism through the positioning block. When the sliding member moves rightward, the outlet is opened. On the contrary, when the sliding member moves leftward, the outlet is closed.
When the toner cartridge is not in use or is in carrying, the sliding member may be unintentionally touched and driven by an external force to move rightward, resulting in leakage of the toner as the outlet is opened. Besides, when the toner cartridge is inserted into the photocopier, the sliding member may be also driven to move by the friction between the sliding member and a housing of the photocopier. In order to prevent this situation, the size of the sliding member or the size of the casing has to be especially designed so as to enhance the friction between the sliding member and the casing, such that the sliding member won't be easily driven to move relative to the casing by an external force. However, the larger the friction between the sliding member and the casing is provided, the harder the sliding member can be driven by the positioning mechanism to move relative to the casing, resulting in that the sliding member may not be smoothly actuated. Therefore, it is a need to provide an improved toner cartridge.